The present invention relates to an internal combustion engine and, more particularly, to an overhead cam shaft type internal combustion engine in which a valve actuating mechanism is accommodated in a space defined by both a cylinder head and a head cover joined to the upper face of the cylinder head.
Where an internal combustion engine of the above-specified kind is constructed to have cylinders in a vertical or V-type configuration and is mounted on the body frame of a motorcycle, for example, just below the main tube of the frame thereof, the main tube comes close to the head cover of the cylinder head. If the height thereof is lowered to enable setting the height of the motorcycle at a low level, the gap between the main tube and the head cover is narrowed and this results in workability problems in attaching and detaching the head cover in the adjustment of a valve actuating mechanism, because the valve actuating mechanism protrudes from the upper face of the cylinder head.